A damper device is provided so that a lid member of a glove box of a vehicle is opened slowly. This damper device functions to enable the lid member to be opened gently due to a damping force, while the damper device functions to enable the lid member to be closed easily with little resistance when the lid member is closed.
For example, Patent Document 1 discloses a damper device which includes a cylinder, a piston which can move in an axial direction within the cylinder, and a seal ring which is positioned on an outer circumference of the piston to seal up a space defined between the cylinder and the piston.
The piston disclosed in Patent Document 1 has a pair of flanges which are provided on the outer circumference thereof so as face each other in the axial direction, cut-out portions which are formed individually on the flanges and a groove which is formed on an outer circumferential surface of the piston where the cut-out portions are formed. The seal ring disclosed in Patent Document 1 is disposed between the pair of flanges of the piston, so that the seal ring can enter the cut-out portions by being deformed partially. When the piston is actuated to operate, the seal ring is caused to enter the cut-out portions due to an air pressure to allow an interior space of the piston to communicate with an exterior space of the piston.